Item metadata is important for online auction sites, as well as for other e-commerce sites. This metadata can be used for multiple purposes, including search, catalog and categorization, financial analytics, and data retention. The product identification (ID) assigned to an item being offered for sale is an important piece of metadata in certain e-commerce sites (e.g., eBay) since items can be transient, as they represent the actual deal or offer. Assigning a product ID to an item may provide advantages, specifically, category data, inventory intelligence, and item default inputs such as stock photo. Other item metadata may be useful as well. However, sometimes certain metadata for an item listing may be missing or may be incorrectly assigned.